Expansion joint assembly for ceiling grid system

ABSTRACT

An expansion joint assembly for the grid system of a suspended ceiling subject to severe expansion and contraction forces caused by temperature changes. The aligned ends of main grid members are joined together by a one piece expansion joint control member having provision for limited lost motion and including tangs designed for limited deflection in response to either expansion or contraction of the grid members. By this technique stresses acting lengthwise of the main grid members are distributed from end to end of the grid members in any row, the tangs flexing if necessary to absorb and accommodate further expansion or contraction. The control member of the joint assembly also includes tabs having multiple functions including holding a grid joint assembled and limiting expansion and contraction as well as excessive flexing of the tangs.

United States Patent 1191 Spencer et al. Jan. 1, 1974 [5 EXPANSION JOINT ASSEMBLY FOR 3,l89.l38 6/1965 Znamirowski 287/l89.36 A CEILING G S S 3,350,125 l0/l967 Adams 287/l80.36 A

[75] Inventors: William H. Spencer, La Canada; Primary Exuminer Reina|dO Machado i 21 f C l f .l:rir i a A!t0rneyWilliam Douglas Sellers et al.

0 0 a1.; es rown, Grants P358, Oreg. Assigneei Trend Ceilings Systems m, Los An expansion joint assembly for the grid system of a Angeles, Calif. suspended ceiling subject to severe expansion and [22] Filed: Jan. 27 1972 contraction forces caused by temperature changes.

The aligned ends of main grid members are joined to- PP 221,142 gether by a one piece expansion joint control member having provision for limited lost motion and including 52 us. c1. 52/758 1) 52/573 403/28 angs designed limited deflect respmse 511 lm. c1. E042/42 1564b 1/68 expansim cmmctim grid members BY [58] Field 01 Search 287/189.36 A- technique Stresses acting lengthwise the main 52/726 573 665 667 668 DIG grid members are distributed from end to end of the grid members in any row, the tangs flexing if necessary [56] Reerences Cited to absorb and accommodate further expansion or contraction. The control member of the joint assembly UNITED STATES PATENTS also includes tabs having multiple functions including 2,689,630 9/l954 Dll'lll'y 287/l89.36 A a joint assembled and expansion and contraction as well as excessive flexing of the 2,830,683 4/1958 Griffith...... 11:: 287/189I36 A tangs' 2340.200 6/1958 Wong 287118936 A 16 Claims, 5 Drawing Figures PATENTEU 3.782.055

A TTGE/VEVEE EXPANSION JOINT ASSEMBLY FOR CEILING GRID SYSTEM This invention relates to suspended ceilings, and more particularly to a novel expansion joint assembly interconnecting the aligned ends of grid members in a manner providing for controlled expansion and contraction in a manner avoiding distortion, buckling, twisting and warping of the ceiling structure.

Larger suspended ceiling systems utilizing a grid network to support ceiling tiles and associated auxiliaries are subject to expansion and contraction due to temperature changes and other causes. The attending stresses can cause serious distortion, warpage, twisting and buckling of the grid network and this can lead to displacement and damage to thetiles as well as dislocation of the ventilating system joints, unsightly ceiling conditons and other serious results well known to constructors and users of suspended ceiling systems. Additionally, such expansion and contraction stresses can result in jamming and malfunctioning the ventilating regulators commonly located in air vents forming part of the ceiling system.

Accordingly, it is a primary object of the present invention to provide a simple, rugged, inexpensive, easily installed expansion joint between adjacent ends of grid members of a ceiling grid network.

Another object of the invention is the provision of a combination grid connector and expansion control member for use in a suspended ceiling.

Another object of the invention is the provision of a one piece connector for use in interconnecting the adjacent ends of a pair of ceiling support grid members.

Another object of the invention is the provision of an expansion control member for use in interconnecting the adjacent ends of a pair of ceiling suspension grid members and arranged to permit limited lost motion therebetween which is restricted to a vertical plane while strongly resisting relative twisting and bending.

Another object of the invention is the provision of an expansion joint for ceiling grid systems including provision for assuring the presence of a gap of predetermined size between the ends of adjacent grid members at the time of installation and including provision for expansion and contraction as well as distribution of stresses to other parts of the grid system.

These and other more specific objects will appear upon reading the following specification and claims and upon considering in connection therewith the attached drawing to which they relate.

Referring now to the drawing in which a preferred embodiment of the invention is illustrated:

FIG. 1 is a side elevational view of a preferred embodiment of the invention and showing the parts of the joint as initially assembled;

FIG. 2 is a view similar to FIG. I but taken from the opposite side of the joint;

FIGS. 3 and 4 are cross sectional views on an enlarged scale taken along lines 33 and 4-4 on FIG. 1; and

FIG. 5 is a plan view of the expansion control member as blanked from sheet stock;

Referring initially more particularly to FIGS. 1 and 2, there is shown an illustrative embodiment of the invention joint, designated generally 10, and including a combination assembly and expansion control member 11 interconnecting the adjacent ends of a pair of identical extruded aluminum grid members 12, 13. Grid members 12, 13 may have various cross sectional shapes but, as herein shown by way of example in FIGS. 3 and 4, the grid members are of T-shape in cross section. The T-stem or upright flange 15 is relatively wide and its upper edge portion 16 is thickened to reinforce and strengthen the grid member. The T-head 18 is here shown as channel shaped, but it may be of any suitable design well known to those skilled in the art. The T- head provides supporting surfaces 19, 19 for the ceiling tiles, parts of the room ventilating system, lighting fixtures and similar auxiliaries commonly forming a part of this type of ceiling system. Since these details are well known and form no part of the present invention. further description of these may be dispensed with.

The end portions of flanges 15 of the grid members 12 and 13 have portions punched out to provide in each a large area rectangular opening 22 and a pair of relatively long but narrow openings 23, 23 located to either side of the longitudinal center line of flange 15, as is best illustrated in FIGS. 1 and 2. Each of the openings 22 and 23 have multiple important functions as will be described in greater detail presently following a description of features of the expansion control member 11.

Expansion control member 11 is here shown as blanked in a single piece from heavy gauge sheet stock and, as initially blanked, has the configuration shown in FIG. 5. This member includes a long, narrow, main body 26 preferably formed with a long bead 27 (FIGS. 1 and 4) terminating short of its opposite ends and serving to reinforce and strengthen the main body against twisting and bending. Projecting from either side of its mid portion are L-shaped tangs 28, 29 A transversely related pair of tangs 28, 29 will be noted as facing in opposite directions. Tangs28 and 29 are bent along crease lines 30 so that one portion 31 thereof lies normal to the edge of member 11. The tangs 28,29 are then deformed inwardly in opposite directions to lie at a suitable angle such as 45 degrees to the length of the control member and with their remotely spaced transverse edges 32, 32 (FIG. 2) having a close fit with the adjacent edge of the large area openings 22. In this connection attention is invited to'FIG. 2 showing the flexible tangs 28, as initially assembled in the grid members l2, l3, cooperating with the edges of the respective openings 22, 22 to hold the ends of grid members 12,13 spaced apart by a narrow gap 35 thereby assuring that there will be ample room for expansion of the two grid members before contacting one anther. It will be recognized that this expansion and the narrowing the gap 35 is accompanied by flexure or deflection of each of tangs 29, 29 whereas tangs 28, 28 are relieved of any load.

Referring again to FIG. 5, it is pointed out that the opposite ends of member 11 include a second set of tabs or assembly lugs 36, 36 projecting directly outwardly from the opposite edges of main body 26. These tabs have multiple functions and are initially folded toward one another along fold lines 37 to lie parallel to one another with their free ends properly spaced apart for assembly through openings 23, 23. Tabs 36 have a transverse width substantially less than the length of openings 23 and are so positioned relative to flexible tangs 28, 29 at the time of initial assembly that their edges are spaced generally equally from either end of openings 23. Thus tabs 36 are midway between the opposite ends of openings 23 and spaced therefrom by a distance approximating the maximum expansion and contraction capabilities of the particular grid members with which they are to be used. Thus, the opposite lateral edges of tabs 36 are so positioned relative to the adjacent ends of openings 23 as to supplement tangs 28, 29 in limiting relative expansion and contraction movement occurring at a particular one of the grid system joints.

ln use, a pair of grid members 12 and 13 are held in general alignment and slightly spaced apart while member 11 is inserted from one side following which tabs 36 are clenched over snugly against the adjacent face of the upright flanges 15 of the two grid members thereby locking the two members rigidly aligned with one another. At this time the transverse corners 32, 32 of tangs 28, 29 will be close to or bearing lightly against the longer edges of openings 22 and in position to absorb load if the grid members tend to expand or contract in response to temperature changes. For example, if there is a rise in temperature, each of the grid members will expand lengthwise with the result that tangs 28, 29 will, in all likelihood, be placed under stress and will deflect or flex toward one another as gap 35 becomes narrower. lt will be understood that tangs 28, 29 may be of tempered resilient material if desired in which case they will flex back toward their original cindition as the temperature falls and the grid members contract. If on the other hand, the ambient temperature falls below the original assembly temperature, the grid members will contract as gap 35 widens and tangs 28, 28 are placed in stress and flexed inwardly. As the temperature rises the grid members will expand and the flexible tangs 28, 28 will resume their former positions.

It is also pointed out that as expansion and contraction occur the very substantial strength of the flexible and resilient tangs 28, 29 is effective to transmit forces lengthwise of the grid members so as to cooperate with similar actions occurring in other similar joints to that just described and understood as located either at all joints between grid members or at selected points judiciously and appropriately distributed in the grid system. It will also be understood that the described expansion joint will be suitably located at joints between transverse elements of the grid system if the width of a particular ceiling system is sufficiently great to warrant the use of expansion joints in its transverse grid members.

It will also be evident from FIGS. 1 and 2 that as either tangs 28 or tangs 29 approach maximu flexed condition the associated one of the lateral edges of assemly tangs 36 will contact one end of opening 23. Thus, under these conditions of maximum loading, tangs 36 will thereafter assume a major portion of any additional load and stress condition in the grid system and thereby serve to greatly supplement the tangs 28 or 29 as the case may be.

While the particular expansion joint assembly for ceiling grid system herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiment of the invention and that no limitations are intended to the detail of construction or design herein shown other than as defined in the appended claims.

We claim I. An expansion joint interconnecting the normally spaced apart aligned adjacent ends of first and second aluminum ceiling support grid members, said grid members each having a normally horizontally extending flange lying in an upright plane, said flanges each having at least one opening, an expansion control member overlapping said openings and extending along one face of said upright flanges with load absorbing tangs extending therefrom into respective ones of said open ings, said tangs having a portion thereof inclined to the length of said flanges with a free end edge thereof located initially substantially against ajuxtaposed edge of the associated one of said openings and cooperating therewith to hold the adjacent ends of said grid members normally spaced apart by a predetermined distance and to resist movement of said grid members relative to one another, and means holding said control member assembled to said first and second members without restricting longitudinal movement of said first and second members relative to one another under normal thermal expansion and contraction conditions.

2. An expansion joint as defined in claim 1 characterized in that said means holding said expansion control member includes lugs clenchable about a portion of each of said grid members and along axes parallel to the length of said grid members.

3. An expansion joint as defined in claim 1 characterized in that said tangs include a plurality thereof on each end portion of said expansion control member positioned in and closely adjacent a respective one of the opposite ends of an associated one of said openings in the upright flange of said first and second grid members.

4. An expansion joint as defined in claim 3 characterized in that the tangs on each end of said control member are inclined in opposite directions and cooperate with an associated opening to urge a juxtaposed one of said first and second members toward and away from one another depending upon the direction of the ambient temperature change.

5. An expansion joint as defined in claim 4 characterized in that said plurality of tangs are spaced widely from one another on the opposite sides ofthe longitudinal center line of said grid members.

6. An expansion joint as defined in claim 1 characterized in that said openings in said upright flanges extend crosswise of the width thereof, said tangs on said control member extending into said openings near the upper and lower edges of said upright flanges and at the diagonally opposed portions thereof, said tangs being inclined oppositely to one another and relative to the longitudinal center line of said upright flanges.

7. An expansion joint as defined in claim 1 characterized in that said tangs are flexible.

8. An expansion joint as defined in claim 1 characterized in that said tangs are resilient.

9. An expansion joint assembly for use in interconnecting the adjacent ends of a plurality of aligned ceiling support grid members and capable of restraining the same against relative rotary movement about their longitudinal axes, said grid members including wide upright flanges formed adjacent their ends with long wide openings, an elongated expansion control member formed from heavy gauge sheet metal sized to lie against said upright flanges in an area bridging the adjacent spaced apart ends thereof, said control member having tangs projecting from the opposite lateral portions thereof and projecting into the diagonally opposed corners of said openings, each of said tangs including a free end portion projecting and inclined oppositely to one another with an end edge of each positioned in close proximity to the opposed edges of an associated one of said openings and in position to engage one of said edges depending upon whether said grid members expand or contract in response to a change in ambient temperature, and means holding said expansion control member assembled across the aligned ends of said grid members.

10. An expansion joint as defined in claim 9 characterized in that said means holding said expansion control member assembled to said grid members comprises tabs integral with said control member and having their ends extending through openings in said grid members and clenched over one edge thereof.

11. An expansion joint as defined in claim 10 characterized in that said openings are so proportioned relative to said clenched tabs as to permit limited relative movement of said grid members in opposite directions lengthwise of said grid members.

12. An expansion joint as defined in claim 9 characterized in that the flanges of said grid members are formed with a plurality of elongated narrow openings disposed along the opposite lateral edges of said control member near the opposite ends thereof, and assembly tabs projecting from the lateral edges of said control member disposed to fit into a respective one of said long narrow openings as said control member is moved into assembly position over one end thereof, the portions of said tabs projecting beyond the other ends of said openings being clenchable to lock said control member loosely and slidably assembled to said grid members.

13. An expansion joint as defined in claim 12 characterized in that said tabs are initially assembled to lie between the opposite ends of elongated openings and cooperating with one or the other ends thereof to limit relative movement of said grid members lengthwise of one another.

14. An expansion joint as defined in claim 9 characterized in that said tangs are deflectable in response to contraction and expansion of said grid members due to temperature changes and effective to transfer stresses between grid members via said expansion control members thereby to distribute stresses lengthwise of a ceiling grid system.

15. An expansion joint as defined in claim 9 characterized in that said tangs flex in response to thermal expansion and contraction of said grid members thereby to distribute stresses lengthwise of said grid members.

16. An expansion joint as defined in claim 9 characterized in that said tangs are resilient and effective to transmit stresses between said grid members by way of said expansion control member.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,7 55 Dated Januar l, 197i;

Inventor) William H. Spencer, et a1,

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 2, line 3, after member insert assembled to said first and second grid members Signed and sealed this 30th day of April 197M.

(SEAL) Attest:

EDWARD I' LFLETCHERJH. C MARSHALL DANL Attes ting Officer Commissioner of Patents uscOMM-Dc 60376-P69 i: u.s. GOVERNMENT PRINTING OFFICE i969 o-sse-su.

FORM o-goso uo-gss 

1. An expansion joint interconnecting the normally spaced apart aligned adjacent ends of first and second alUminum ceiling support grid members, said grid members each having a normally horizontally extending flange lying in an upright plane, said flanges each having at least one opening, an expansion control member overlapping said openings and extending along one face of said upright flanges with load absorbing tangs extending therefrom into respective ones of said openings, said tangs having a portion thereof inclined to the length of said flanges with a free end edge thereof located initially substantially against a juxtaposed edge of the associated one of said openings and cooperating therewith to hold the adjacent ends of said grid members normally spaced apart by a predetermined distance and to resist movement of said grid members relative to one another, and means holding said control member assembled to said first and second members without restricting longitudinal movement of said first and second members relative to one another under normal thermal expansion and contraction conditions.
 2. An expansion joint as defined in claim 1 characterized in that said means holding said expansion control member assembled to said first and second grid members includes lugs clenchable about a portion of each of said grid members and along axes parallel to the length of said grid members.
 3. An expansion joint as defined in claim 1 characterized in that said tangs include a plurality thereof on each end portion of said expansion control member positioned in and closely adjacent a respective one of the opposite ends of an associated one of said openings in the upright flange of said first and second grid members.
 4. An expansion joint as defined in claim 3 characterized in that the tangs on each end of said control member are inclined in opposite directions and cooperate with an associated opening to urge a juxtaposed one of said first and second members toward and away from one another depending upon the direction of the ambient temperature change.
 5. An expansion joint as defined in claim 4 characterized in that said plurality of tangs are spaced widely from one another on the opposite sides of the longitudinal center line of said grid members.
 6. An expansion joint as defined in claim 1 characterized in that said openings in said upright flanges extend crosswise of the width thereof, said tangs on said control member extending into said openings near the upper and lower edges of said upright flanges and at the diagonally opposed portions thereof, said tangs being inclined oppositely to one another and relative to the longitudinal center line of said upright flanges.
 7. An expansion joint as defined in claim 1 characterized in that said tangs are flexible.
 8. An expansion joint as defined in claim 1 characterized in that said tangs are resilient.
 9. An expansion joint assembly for use in interconnecting the adjacent ends of a plurality of aligned ceiling support grid members and capable of restraining the same against relative rotary movement about their longitudinal axes, said grid members including wide upright flanges formed adjacent their ends with long wide openings, an elongated expansion control member formed from heavy gauge sheet metal sized to lie against said upright flanges in an area bridging the adjacent spaced apart ends thereof, said control member having tangs projecting from the opposite lateral portions thereof and projecting into the diagonally opposed corners of said openings, each of said tangs including a free end portion projecting and inclined oppositely to one another with an end edge of each positioned in close proximity to the opposed edges of an associated one of said openings and in position to engage one of said edges depending upon whether said grid members expand or contract in response to a change in ambient temperature, and means holding said expansion control member assembled across the aligned ends of said grid members.
 10. An expansion joint as defined in claim 9 characterized in that said means holding said expansion coNtrol member assembled to said grid members comprises tabs integral with said control member and having their ends extending through openings in said grid members and clenched over one edge thereof.
 11. An expansion joint as defined in claim 10 characterized in that said openings are so proportioned relative to said clenched tabs as to permit limited relative movement of said grid members in opposite directions lengthwise of said grid members.
 12. An expansion joint as defined in claim 9 characterized in that the flanges of said grid members are formed with a plurality of elongated narrow openings disposed along the opposite lateral edges of said control member near the opposite ends thereof, and assembly tabs projecting from the lateral edges of said control member disposed to fit into a respective one of said long narrow openings as said control member is moved into assembly position over one end thereof, the portions of said tabs projecting beyond the other ends of said openings being clenchable to lock said control member loosely and slidably assembled to said grid members.
 13. An expansion joint as defined in claim 12 characterized in that said tabs are initially assembled to lie between the opposite ends of elongated openings and cooperating with one or the other ends thereof to limit relative movement of said grid members lengthwise of one another.
 14. An expansion joint as defined in claim 9 characterized in that said tangs are deflectable in response to contraction and expansion of said grid members due to temperature changes and effective to transfer stresses between grid members via said expansion control members thereby to distribute stresses lengthwise of a ceiling grid system.
 15. An expansion joint as defined in claim 9 characterized in that said tangs flex in response to thermal expansion and contraction of said grid members thereby to distribute stresses lengthwise of said grid members.
 16. An expansion joint as defined in claim 9 characterized in that said tangs are resilient and effective to transmit stresses between said grid members by way of said expansion control member. 